Vulnerability in Linux

[ Description ]Official description

In the Linux kernel, the following vulnerability has been resolved: smb: client: fix server->total_read for compound encrypted PDUs In receive_encrypted_standard(), server->total_read is left at the full decrypted frame size when walking sub-PDUs of a compound encrypted frame. As a result, cifs_handle_standard() passes this full size to smb2_check_message(), causing the PDU length guards to incorrectly validate the entire compound frame instead of the current sub-PDU. This allows truncated non-last sub-PDUs to bypass length validation, leading to out-of-bounds reads in smb2_get_data_area_len(). Fix this by setting server->total_read to the true length of the current sub-PDU: next_cmd for non-last sub-PDUs, and the remaining pdu_length for the last one.

[ Fixes ]Fixes and patches

No fix or interim patch is linked from our sources yet. Check the vendor references below and limit exposure of affected systems until a fix is available.

[ Advisories ]Government CERT advisories

• BSI CERT-Bund5 Oct 2026WID-SEC-2026-3743

  Linux Kernel: Multiple vulnerabilities Translated from German

  Risk mediumCVE-2026-98221CVE-2026-98181CVE-2026-98248+204 more CVEs

[ References ]References

• git.kernel.org/stable/c/282b72f9a7ef31296c48366db4128882999cc048
• git.kernel.org/stable/c/8703539d22fdbc13dd2db090ee199c3a427b8ea0
• git.kernel.org/stable/c/a46eb242e9eef3a3897d166748b23303c516e870
• git.kernel.org/stable/c/e78fc1d240b27349b45a0f1c3e3c2c401d7e230d
• git.kernel.org/stable/c/ebb8a075fdc7af3d196a4f158a0e18dbc394c0e3
• git.kernel.org/stable/c/f73726b83e4756fdaa099e1bc1143293bd57ad79